Interesting. Both are great frameworks. My thoughts are: I like how django lacks all that directory structure and you can easily use a single file for your models. Django templates are way more powerful and safer than erb / haml, etc. I wish there was a port of django templates in ruby. If so my preferred environment would be sinatra + datamapper + django templates.
There's also mustache ( http://github.com/defunkt/mustache ) which has some similarities to django templates and is pretty popular. "safer than erb / haml, etc" Are you are referring to auto-escaping strings? If so, in Rails 3, this is on by default, and for Haml without Rails it's a simple setting.
I was referring to the auto-escaping as well as to the inability to run arbitrary code inside a template (for all I know this feature is added to the newest versions, though)